Non-rotating two-part mandrel and a method of forming spiral-seamed pipe

ABSTRACT

A tower houses a forming mill which shapes and feeds forward a strip of metal having an upstanding male locking hook along one edge and an upstanding downwardly opening female locking strip along the other edge. A substantially semicylindrical mandrel lower part has an end secured to the tower and projects horizontally outward under the mill at an angle to the strip. The mandrel upper part has a flat plate pivotally connected to the lower part and bears a way in which a slide carrying a curved guide plate is adjustably positioned. The mandrel parts may be adjusted angularly in a horizontal plane and locked in position and the slide is linked to a turntable slide carrying a lower pinch roll which may be angularly and vertically adjusted in position. The tower carries an upper pinch roll and a bending roll for bending the strip downward. The bent strip is guided angularly and downwardly by the forward side of the mandrel lower part toward an exit conveyor for carrying away the formed pipe. As each turn of strip around the mandrel approaches the top it is angularly guided by the curved guide plate so that the male locking hook of the turn engages the female hook of the next turn and the pinch rolls clinch the hooks for continuously forming the spiral-seamed pipe.

United States Patent [191 Lombardi Jack P. Lombardi, R.D. Duguid Rd., Manlius, NY. 13104 [22] Filed: Sept. 12, 1974 [21] Appl. N0.: 505,505

[76] Inventor:

[52] US. Cl 72/49; 29/477.3; 29/200 B [51] Int. Cl. B210 37/12 [58] Field of Search 72/49, 50, 135; 129/4773, 29/200 B [5 6] References Cited UNITED STATES PATENTS 12/1958 Jensen ..72/49 9/1971 Lewis 72/135 Primary Examiner-C. W. Lanham Assistant ExaminerRobert M. Rogers Attorney, Agent, or FirmBruns & Jenney [57] ABSTRACT A tower houses a forming mill which shapes and feeds [451 Aug. 12, 1975 forward a strip of metal having an upstanding male looking hook along one edge and an upstanding downwardly opening female locking strip along the other edge. A substantially semicylindrical mandrel lower part has an end secured to the tower and projects horizontally outward under the mill at an angle to the strip. The mandrel upper part has a flat plate pivotally connected to the lower part and bears a way in which a slide carrying a curved guide plate is adjustably positioned. The mandrel parts may be adjusted angularly in a horizontal plane and locked in position and the slide is linked to a turntable slide carrying a lower pinch roll which may be angularly and vertically adjusted in position. The tower carries an upper pinch roll and a bending roll for bending the strip downward. The bent strip is guided angularly and downwardly by the forward side of the mandrel lower part toward an exit conveyor for carrying away the formed pipe. As each turn of strip around the mandrel approaches the top it is angularly guided by the curved guide plate so that the male locking hook of the turn engages the female hook of the next turn and the pinch rolls clinch the hooks for continuously forming the spiral-seamed pipe.

6 Claims, 20 Drawing Figures PATENTEU Am; I 21975 SHEET PAIENTEU AUG 1 21975 SHEET Q. r vvvy ,898 826 PATH-HEB AUG 1 21975 3 SHEET 4 PATENTEU AUG 1 2 1975 SHEET NON-ROTATING TWO-PART MANDREL AND A METHOD OF FORMING SPIRAL-SEAMED PIPE BACKGROUND OF THE INVENTION This invention relates to apparatus for making spiralseamed pipe and more particularly to a non-rotating two-part mandrel which can be quickly adjusted for making spiral-seamed pipe of different diametrical sizes.

I-Ieretofore spiral-seamed pipe has been usually made on rotating cylindrical mandrels, a different mandrel being required for each diameter of pipe, or have been made using a plurality of curve-plates and rollers attached to a framework requiring a different adjustment of each plate and roller when the diametrical size of pipe being produced is changed. The readjustment of rollers and the changing of parts for changing from one pipe size to the other requires considerable time resulting in loss of use of the machine each time the machine is readjusted.

The principal object of the present invention is to provide a mandrel for producing spiral-seamed pipe which can be quickly and accurately readjusted for producing pipes of different diametrical sizes.

SUMMARY OF THE INVENTION The present invention contemplates a two-part mandrel, the two parts being connected by a pivot pin and being angularly adjustable about the pin in a horizontal plane for different diameters of pipe. Provision is made for locking the parts in the selected adjusted position.

Like other spiral-seamed pipe machines, the metal for the pipe is supplied by forming a strip in a conventional forming mill, the strip being continuously drawn in one or more layers from a roll or rolls of sheet metal, usually steel. The forming mill has synchronously driven rollers for forming the strip, as for corrugating one or all layers and also for forming an upstanding male location hook along one edge and an upstanding and downwardly opening female locking hook along the opposite edge. A conventional bending roll bends the formed strip as it comes off the mill and is continuously fed forward by the rollers of the mill.

The mandrel lower part is substantially semicylindrical for the major and outer portion of its length and has its inner end secured to a support, such as a tower, under the forming mill and it projects horizontally out from under the mill at an angle to the forward path of the strips so that the female hook at the outer edge of the strip passes above and aligned with the axis of the pivot pin. The top surface of the lower part is flat along the major and outer portion of its length and as the downwardly bent strip passes around the mandrel it is angularly guided by the forward side of the mandrel lower part.

The mandrel upper part has a flat rectangular plate at its bottom through which the pivot pin passes and the plate carries a Way in which a slide is guided longitudinally of the plate. The slide carries an upwardly convex, curved guide plate which may conveniently be of the same radius of curvature as the side of the lower part, the guide plate being pivotally secured to the slide along one side so as to be tiltable upward with respect to the slide. An hydraulic cylinder carried by the slide is provided for selectively tilting the guide plate upward.

The inward end of the slide is linked by a channeltype connector to a second slide carrying a turntable. The turntable is capable of a limited angular adjustment and means are provided for locking the turntable in adjusted position.

The turntable carries a support for a roller shaft which rotatably supports a lower pinch roll, the upper pinch roll being adjustably carried by the tower outside the formed pipe. The lower pinch roll shaft has ends radially offset from the roller carrying center of the shaft and means are provided on the turntable for rotating the shaft so that the roller may be adjusted up and down with respect to the way.

Screw and nut means are provided on the slide and way so that the slide and turntable may be selectively positioned along the way.

When changing pipe, size the angular adjustment of the mandrel parts is first made and then the first turn of the strip is drawn down against the lower part, then around the mandrel and against the guide plate, and the guide plate is raised or lowered so that the male locking hook at the leading end of the first turn is directed toward the downward opening of female hook of the second turn, the curved guide plate angularly guiding the first turn in this direction.

The upper and lower pinch rolls are then adjusted for clinching the hooks for forming the seam. The pipe can then be continuously formed.

An exit conveyor is provided for rotatably supporting the formed pipe and carrying it away from the mandrel as it is formed. The conveyor is pivotally attached to the tower for angular adjustment to carry the formed pipe. The conveyor platform carries longitudinally extending rollers on which the formed pipe may rotate as the formed pipe is pushed away from the mandrel by the formation process. The conveyor platform is vertically adjustable and the conveyor roller spacing is adjustable so that the conveyor rollers may be positioned to rotatably support formed pipe of widely different diametrical sizes.

It has been found in practice that, whereas the machine adjustment of the rotating type mandrel consumed at least a half of a working days time, it requires only about a half hour to adjust the mandrel of the present invention when the pipe size is changed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a mandrel according to the invention, certain parts being omitted for clarity;

FIG. 2 is a side elevational view of the lower part thereof;

FIG. 3, on sheet two of the drawings, is an end elevational view thereof as viewed from the left in FIG. 2;

FIG. 4 is a plan view thereof;

FIG. 5 is a plan view of the mandrel upper part, certain parts being omitted for clarity;

FIG. 6 is an end view of a portion thereof as viewed from the left in FIG. 5;

FIG. 7 is an end view of the slide and way portion of the mandrel upper part as viewed from the left in FIG.

FIG. 8 is a sectional view on the line 8-8 of FIG. 5;

FIG. 9, on sheet three of the drawings, is a plan view on an enlarged scale of the slide and way portion of the mandrel upper part, the curved guide plate being elevated;

FIG. is a sectional view on line 10l0 of FIG. 9, the guide plate being in normal position;

FIG. 11 is a side elevational view of a portion of the slide portion of the mandrel upper part, the connection between slide and turntable being in section on the line 11-11 of FIG. 9;

FIG. 12 is a longitudinal sectional view on an enlarged scale of the pinch roll and its support shown in FIG. 9;

FIG. 13 is a sectional view on the line 13-13 of FIG.

FIG. 14 is an end view of the pinch roll and its sup port as viewed from the right in FIG. 9;

FIG. 15, on sheet 5 of the drawings, is a plan view on a reduced scale of the mandrel and its support and associated structure;

FIG. 16 is a perspective, fragmentary view, on an enlarged scale, of the mandrel and its associated structure, details of the turntable being omitted for clarity;

FIG. 17, on sheet 4 of the drawings, is a perspective view on a reduced scale of a portion of pipe formed on the mandrel and the mandrel as viewed from the left in FIG. 16;

FIG. 18 is a fragmentary, transverse sectional view of the metal strip fed to the mandrel as indicated in FIG. and

FIGS. 19 and 20 are fragmentary sectional views, respectively, of two turns of strip interengaged, and two interengaged turns with the seam clinched.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, a two-part or portion mandrel 21 comprises a lower part 22 and an upper part 23 shown with slide and way portions omitted.

As best seen in FIGS. 2, 3 and 4, the lower part 22 comprises a steel tube which has been cut down, except for a portion 24 (FIG. 4) at one end and a fragmentary portion 25 (FIGS. 2 and 4) at the same end along one side, to a generally semicylindrical configuration and provided with a flat plate 26 welded, as best seen in FIG. 3, to the cut-down tube to provide a fiat top surface extending along the major portion of the length of part 22. Referring to FIG. 3, it will be seen that, by addition of the plate 26, the left hand end of the part exceeds a semi-cylinder.

For forming pipe of varying diametrical sizes from 12 inches to 96 inches inside diameter, the outer surface of the part 22 is machined and polished to a diameter of a fraction of an inch less than 12 inches. Vertically extending reinforcing ribs 27 and 28 are provided, as shown in FIG. 3. As shown in FIG. 4, corners of the ends are cut away at 29 and 30, the latter being filled and rounded as shown in FIG. 3 to provide relief from interference at this end in producing some of the smaller sizes of pipe.

At the right in FIGS. 2 and 4 a carefully located rod 31 is fitted vertically with respect to the top of plate 26 and fixed by welding, its ends extending trunnion-like above and below part 22 and through portion 24. This provides means for attaching the part 22 to its support and this end is hereinafter called the inner end.

As best seen in FIG. 2, a slot 32 is cut between a laterally projecting ear 33 and plate 26, it being noted that a corresponding slot is cut through the reinforcing rib 28. Two spaced ears 34 adjacent ear 33 project laterally from the lower portion of part 22, as best seen in FIG. 3, the ears being attached by welding.

Approximately midway between slot 32 and the left end (FIGS. 2 and 4) of part 22 a vertically extending hole is cut in plate 26 and rib 27 and pivot pin 35 is secured by welding in the hole projecting upward from plate 26. The end of the part'to the left of pin 35 is hereinafter referred to as the outer end.

Referring now to FIGS. 5 and 6, the mandrel part 23 comprises a rectangular metal bottom plate 36, a pivot pin hole 37 extending through this plate, and an extension arm 38 welded to the plate 36. At the inner end of arm 38 an arcuate clamping wing 39 is secuerd by welding, fillets being provided at 40 and 41 for additional strength. Wing 39 has an arcuate slot 43 therethrough as shown. When the mandrel is assembled with the pivot pin 35 extending through the hole 37, part 23 is then swung so that wing 39 extends through slot 32.

The top surface of part 22 and the bottom surface of plate 36 being ground and polished flat, the mandrel parts 22 and 23 can thereafter be easily adjusted through a range of angles and wing 39 can then be locked in position by a clamping bolt 44, passing through slot 43 of the wing and an appropriate hole in ear 33, and clamped to the ear by a nut 45 as shown in FIG. 1.

As shown in FIG. 5, a way 46 is formed on top of plate 36 by gib rails 47 spaced from plate 36 by spacers 48 (FIG. 8). The rails and spacers are secured to plate 36 by a plurality of bolts, not shown, or may be welded in place. An end block 49 (FIG. 7) is bolted to plate 36.

Referring now to FIGS. 9, 10 and 11 a slide 50 is carried in the way 46, the slide having a pair of upwardly projecting hinge members 51 which also project to one side of the way, the forward side, and extend downward outside the gib rail 47 on that side, as best seen in FIG.

An upwardly convex curved guide plate 52 is carried by slide 50. Plate 50 may be made from a portion of the tube cut away to form the mandrel lower part 22 and a pair of spaced hinge ears 53 are welded to plate 52, as shown, a pivot rod 54, passing through appropriate holes in members 51 and ears 53, hingedly connect guide plate 52 to slide 50.

Slide 50 also has an upwardly projecting control block 55 with a hole therethrough as shown. A control bolt 56, best seen in FIG. 16, extends through a threaded hole in end block 49 and through the hole in block 55. A pair of nuts 57 on the bolt on either side of block 55 are prevented from turning on the bolt by pins therethrough so that, as bolt 56 is turned the slide is adjusted in position along the way.

As shown in FIGS. 9 and 10, slide 50 also carries a hydraulic cylinder 60 whose piston ordinarily contacts the under surface of the guide plate 52. As shown in FIGS. 9 and 16, fluid under pressure is supplied by a flexible hose 61 which may be connected to a supply source connected to the support structure for the mandrel 21 and controlled by a valve near the mandrel for selectively raising the guide plate 52.

As seen in FIGS. 9 and 11, slide 50 is connected to a second turntable slide 62 by a channel-type coupling 63. One upstanding flange of the connector 63 is received' in a transversely extending slot 64 in the bottom of slide 50 and the other upstanding flange is arcuate and is received in an arcuate slot 65 in the bottom of the turntable slide 62.

Turntable 62 has projecting plate 66 welded to its top and the projecting portion of the plate overlies a portion of connector 63 which carries an upward projecting bolt anchor 67 welded thereto. The bolt 68 anchored in projection 67 projects upward through an arcuate slot 69 in plate 66 and a nut 70 is provided for locking plate 66 to anchor 67. The arcuate slots are arranged around the center of turntable 66 so that the turntable is capable of limited rotation.

The turntable 62 also carries a U-shaped roller support 70 welded or otherwise secured to the turntable top, the two upwardly projecting legs 71 and 72 of the support being shown in FIG. 9. Referring to FIG. 12, a lower pinch roll 73 is mounted on a shaft 74 by means of a ball bearing assembly 75 whose outer race is anchored in the roll by a snap ring 76. The axis of ends 74a and 74b of shaft 74 are off-center from the rollcarrying center of shaft 74. A bolt 77 engaged in a groove in the end 74a secures the shaft in place and the other end 7411 is splined, as shown in FIGS. 12 and 14.

As shown in FIGS. 9 and 14, a turning ring 78 is secured to the splined end 7412 and ring 78 has a radially projecting flange 79 in which is threaded a bolt 80. The bolt end abuts an upwardly projecting stop 81 secured to a portion of the top of turntable 62 which is adapted to clear the gib rail 47 so that, when the bolt 80 is advanced, the ring 78 and shaft 74 are turned to raise the shaft 74 and pinch roll 73 and the turntable can be turned to adjust the angle that the axis of roll 73 makes with respect to the way 46.

Referring now to FIG. 15, the mandrel lower part 22 is secured to the side ofa supporting tower 82, the trunnion ends of rod 31 being secured in cup like brackets 83, one above and the other below the vertically extending rod 31. A brace rod 84 has one end secured between the ears 34--34 of the mandrel lower part and its other end secured to a bracket 85 fixed to the side of tower 82.

A forming mill 86 is shown in phantom lines in FIG. and the tower 82 is shown in section, it being understood that the mandrel 21 projects from the tower under the forming mill. Such a forming mill is more completely described and shown in US. Pat. No. 3,474,514 issued Oct. 28, 1969 to the inventor herein. Like the forming mill in the aforesaid patent, the mill 86 is adapted to draw an upper strip 87U and a lower strip 87L from respective coils 88U and 88L supported spaced from the tower as shown. Forming mill 86 is also adapted to form a laminated strip 89, also shown in phantom lines, with a corrugated upper layer and an uncorrugated lower layer, the laminated strip having an upstanding locking hook along its inner edge and an upstanding and downwardly opening female locking hook along its outer edge. It will be noted that the female hook is adapted to pass directly over the pivot pin of the mandrel.

Although the mandrel 21 is described herein as adapted to form a spiral seamed corrugated laminated pipe with uncorrugated interior, it will be understood that the mandrel is equally adapted to make un- Iaminated, corrugated or uncorrugated spiral seamed pipe.

Referring to FIG. 16 the mandrel parts 22 and 23 are shown adjusted to a chosen angle and disposed under the discharge end of the forming mill 86. An upper pinch roll 90 is supported on the tower 82, it being understood that the supports 91 for the pinch roll shaft 92 are adjustably secured to the tower. An adjusting screw 93 is provided for adjusting the axis of shaft 92 substantially parallel to the way 46 on mandrel part 23. A conventional bending roll 94 is provided, the stripcontacting portions of the roll being laterally spaced along shaft 95 because the upper surface of the discharged strip is corrugated. The supports 96 for shaft 95 are secured on a slide 97 adjustably secured to tower 82 so that the bending roll 94 may be adjusted downward for forming the smaller sizes of pipe.

Referring to FIG. 17, a spiral-seamed pipe 98 is shown being formed on mandrel 21, the formed strip 89 advancing from the right as seen in this Figure. The first turn 89a of strip 89, bent downward by roll 94 is led downward against the forward side of mandrel part 22 which angularly guides the first turn 89a down. Thence the turn is led upward and forced against the curved guide plate 52, adjusted to position by pressure from the hydraulic cylinder 60. Adjacent and behind plate 52 the seam 99 is formed by pinch rolls 73 and 90 which have been adjusted angularly and vertically. The angle between parts 22 and 23 directs the male locking hook of the first turn into engagement within the downward opening of the female hook of the second turn 89b as it comes out of the forming mill 88 just prior to the clinching of the seam 99. After the first turn the pipe 98 is produced continuously.

Referring now to FIG. 18 a formed strip 89 is shown in section with a male locking hook 100 along one edge and a downwardly opening female locking hook 101 along the opposite edge. It will be noted that the male flange 100 is inclined upward and to the right in this Figure and the outward flange 102 of the female hook is inclined downward and to the left. Referring to FIG. 16 edge guide roll 103 for the formed strip 89 is provided in the shape shown for bending flange 102 inward and a similar guide roll, not shown, at the other side of strip 89 inclines the male flange 100 inward.

Referring to FIG. 19, the male hook 100 of a first turn 89a is shown engaged with the female hook 101 of a second turn just prior to the seam 99 being clinched. In FIG. 20 the clinched seam 99 is shown in cross sec tion.

It will be apparent from inspection of FIG. 17 that the angle which mandrel part 23 makes with part 22 determines the angle at which the formed pipe 98 is forced away from tower 82. For the smaller diameter pipes this angle is small, for the larger diameter pipes the angle is large. A guide line 104 for the edge of plate 36 may be scribed on the top surface of the mandrel lower part for each size of pipe to be produced, as shown in FIG. 1.

Referring again to FIG. 15, a conveyor 105 is provided for carrying away formed pipe 98 as it is formed on mandrel 21. A pair of spaced shafts 106 carried in suitable bearings 107 is secured to longitudinally extending members 108 of a platform 109. It will be understood that a lower framework, not shown, is pivotally secured to tower 82 to pivot horizontally about a point aligned with the axis of pivot pin 35 and this lower framework is provided with castors 110 adapted to follow a track 111 arcuately curved about the pivot point much as shown and described in US. Pat. No. 2,752,873 issued to J. R. Freeze on July 3, 1956.

A similar upper framework, not shown, above mandrel 21 is adapted to pivot about the same axis and the upper and lower frameworks are connected by vertically extending guide rods 112 which pass through appropriate holes in the four corners of platform 109. Brackets 113, adapted tobe engaged by hooks suspended from a factory roof-supported lift, are secured to each member 108 so that platform 109 is adapted to be lifted to any level appropriate to the pipe size being formed. Rollers 114 carried on shafts 106 are adapted to engage and rotate with the formed pipe 98 as it is formed. Collars, not shown, clamped to the rods 112 under platform 109, may be provided for securing the platform at the desired level so that the lift may be used elsewhere in the factory.

Members 108 are preferably adjustable transversely of the platform 109, by means not shown, so that the transverse spacing of rollers 114 may be varied according to the diametrical size of the pipe 98 being formed. It will also be understood that the formed pipe 98 slides on the rollers 114 as the formed pipe is forced away from tower 82 by the formation process, the pushing force being furnished by the synchronously driven rollers of the forming mill 86. The rollers 114 are positioned to support the lower portion of formed pipe 98, as viewed in FIG. 17, as the continuous forming of the pipe takes place.

I claim:

1. A non-rotating two-part mandrel for forming spiral seamed pipe from a formed strip of metal received from a forming mill having synchronously driven rollers for forming an upstanding male looking hook along one edge and an upstanding and downwardly opening female locking hook along the opposite edge, comprising:

a substantially semi-cylindrical lower mandrel part secured at its inner end to a support tower projecting horizontally under the forming mill, a bending roller on the tower for bending the strip downward, the lower part having at its outer end a flat upper surface and a curved side surface on the far side of the advancing strip adapted to angularly guide the strip as it is received from the mill, an upper mandrel part having a flat lower surface plate at its outer end, a pivot pin projecting vertically upward from the flat upper surface through the surface plate and secured to one of the mandrel parts, a way formed longitudinally on the surface plate and carrying a slide adjustable along the way, the slide carrying" a guide plate curved substantially about the midline of the surface plate and adjustable up and down with respect to the plate, the surface plate being angularly adjustable about the pivot pin with respect to the mandrel lower part for forming pipes of different diameters, means for locking the plate in angularly adjusted position, a turntable in the way linked to the slide and carrying a lower pinch roll, the turntable being angularly adjustable with respect to the way and lockable in adjusted position, the lower pinch'roll being adjustable up and down with respect to the surface plate, the lower mandrel post being positioned with respect to the forming mill so that the female hook of the advancing strip passes over the locking pin, the guide plate being adapted to angularly guide the strip so that the male hook of the strip on each succeeding turn of the strip about the mandrel is aligned with and enters the opening of the female hook of the preceeding turn, and an upper pinch roll rotatably carried by the tower, the pinch rolls being adjustable for continuously clinching the hooks into a spiral seam as the strip is fed around the mandrel.

2. A non-rotating two-part mandrel for forming spiral seamed pipe from a formed strip of metal received from a forming mill having synchronously driven rollers for forming an upstanding male locking hook along one edge and an upstanding and downwardly opening female locking hook along the opposite edge, comprising:

a substantially semi-cylindrical lower mandrel part secured at its inner end to a support tower and projecting horizontally under the forming mill, the lower part having a flat upper surface at its outer end, an upper mandrel part having a flat lower surface plate at its outer end, a pivot pin projecting vertically upward from the flat upper surface through the surface plate and secured to one of the mandrel parts, the surface plate having a portion projecting inwardly for moving the plate about the pivot pin to change the angular disposition of the plate with respect to the lower part, means at the inner end of the projecting portion for locking it to the lower part in a selected angular disposition, the surface plate bearing a longitudinally extending gib-way, a first slide in the way bearing a guide plate curved about the axis of the lower part pivotally secured at one side to the upper portion of the slide, motor means carried by the slide for limited adjustment of the guide plate spacing above the slide, means on the mandrel upper part for securing the slide in a selected position along the way, a second slide in the way bearing a turntable and connected by a channel-type coupling to the first slide, the turntable having limited angular adjustment relative to the way, cooperating means on the turntable and coupling for locking the turntable in a selected angular position, a lower pinch roll rotatably carried on the turntable and having an axially extending shaft substantially aligned with the way, the pinch roll shaft ends having their axes off-center from the axis of its roll-bearing center, means on the turn table slide for turning the pinch roll shaft and regulating the height of the pinch roll above the way; the lower mandrel part projecting from the tower at an angle and the forming mill rollers feeding the strip forward with its female hook passing substantially over the inner end of the mandrel and its male hook substantially over the axis of the pivot, an upper pinch roll adjustably and rotatably secured to the tower over the lower pinch roll, at least one bending roller for bending downward the strip advancing from the forming mill, and an exit conveyor for receiving pipe formed on the mandrel.

3. A non-rotating two-part mandrel for forming spiral seamed pipe from a formed strip of metal received from a forming mill having synchronously driven rollers for forming an upstanding male locking book along one edge and an upstanding and downwardly opening female locking hook along the opposite edge, comprisa substantially semi-cylindrical lower mandrel part secured at its inner end to a support tower and projecting horizontally therefrom under the forming mill, the lower part having a flat upper surface at its outer end, an upper mandrel part having a flat lower surface plate at its outer end, a pivot pin projecting vertically upward through the flat upper surface and through the surface plate and being secured to one of the mandrel parts, the surface plate having a portion projecting inwardly and bearing an arcuate clamping plate adjacent the inward end of the lower part and the lower part having a cooperating clamping ear whereby the angular relation of the two parts may be selectively adjusted and then secured by bolt means through the clamping plate and ear, the surface plate bearing a longitudinally extending gib-way, a first slide in the way bearing guide plate curved about the axis of the lower part pivotally secured at its forward side to the slide and hydraulic cylinder means on the first slide for selectively adjusting the guide plate curved surface up and down about its pivoted side, means on the upper part for securing the first slide in a selected position along the way, a second slide in the way bearing a turntable and connected by a channel-type coupling to the first slide, the turntable having limited angular adjustment relative to the way and cooperating means on the turntable and coupling for locking the turntable in a selected angular position, a lower pinch roll rotatably carried on the turntable and having an axially extending shaft substantially aligned with the way and having its ends on an axis off-center from the axis of its roll-bearing center, and means on the turntable slide for turning the pinch roll shaft and thereby regulating the heighth of the pinch roll above the way; the lower mandrel part projecting from the tower at an angle and the forming mill rollers feeding the strip forward with the male hook passing substantially over the inner end of the mandrel and the female hook aligned substantially with and above the axis of the pivot pin, an upper pinch roll adjustably and rotatably secured to the tower over the lower pinch roll, at least one bending roller adjustably secured to the tower for bending downward the strip advancing from the forming mill, and an exit conveyor having spaced rollers for receiving pipe formed on the mandrel, the conveyor being adjustable up and down and angularly with respect to the mandrel; whereby a turn of advancing strip is bent downward and angularly guided by the forward side of the lower mandrel part, then continues downward to be supported by the conveyor rollers, then continues upward and forward angularly guided by the curved guide plate, the male locking hook of each succeeding turn of strip around the mandrel being guided into the downward opening of the female hook of the preceding turn of strip, the two interengaged locking hooks being thereafter bent over and clinched between the two pinch rolls, the angular adjustment and spacing of the two pinch rolls being preset, the position of the curved guide plate being positioned longitudinally of the upper mandrel part for the continuous forming of the spiral pipe seam, and the formed pipe being forced away from the mandrel by the continuous advancing of the strip from the forming mill.

The mandrel defined in claim 3 adapted for receiva laminated strip having a corrugated upper layer a flat lower layer, the bending roller comprising a 'ality of laterally spaced rollers on a common shaft contact with the valleys of the corrugations,

whereby a spiral seamed corrugated laminated pipe with uncorrugated interior is formed.

5. The mandrel defined in claim 3 wherein the major portion of the exterior in cross section of the lower mandrel exceeds a semicircle and wherein the diameter of the semicylindrical lower mandrel part and twice the radius of the curved guide plate of the upper mandrel part are each less than the interior diameter of the smallest pipe to be formed on the mandrel.

6. A non-rotating, adjustable, two-portion mandrel for forming spiral-seamed metal pipes of different diameters from a strip of standard width having an upstanding male locking hook along one edge and an upstanding, downwardly opening female locking hook along the other side; comprising: a substantially semicylindrical lower mandrel portion secured at its inner end projecting horizontally from a support tower and having a flat upper surface over the major and outer portion of its length and circularly curved under and side surfaces for substantially its full length, the curved surfaces extending at least therearound, the radius of curvature thereof being smaller than the radius of curvature of the smallest diameter of pipe to be produced; an upper mandrel portion of less length than the lower portion and including a plate having a flat horizontally-extending lower surface engaging the lower portion upper surface; a vertically extending pivot pin pivotally connecting the upper and lower portions; means on the upper portion for angularly adjusting the upper portion in a horizontal direction with respect to the lower portion, and lock means for securing the upper portion in adjusted position to the lower portion; a slide carried on the upper portion plate, the plate having way means for guiding the slide longitudinally along the plate; means carried on the upper portion for adjusting the slide toward and away from the pivot pin; a turntable adapted to slide along the way means, a channel type connector connecting the turntable to the slide, the turntable being angularly adjustable with respect to the slide, and means for locking the turntable in adjusted position; a lower pinch roll rotatably carried by the turntable, means for raising and lowering the lower pinch roll a limited amount with respect to the upper portion plate; synchronously driven rolls for forming the locking hooks and for driving forward the strip rotatably carried in the tower above the mandrel for feeding the strip toward the mandrel; the mandrel lower portion projecting at an angle to the line of travel of the strip and the pivot pin being positioned to underlie the female locking hook on the outer edge of the strip; an upwardly convex curved guide plate of substantially the same radius of curvature as the mandrel lower portion being pivotally secured along one edge to the slide, motor means carried by the slide for adjustably raising the guide plate; at least one bending roller and an upper pinch roll carried by the tower and each being adjustable with respect to the mandrel; and conveyor means below the mandrel for receiving and carrying away pipe formed on the mandrel; whereby each turn of advancing strip is bent downwardand angularly guided by the forward side of the mandrel lower portion, then continues downward to the region of the conveyor means, thence continues upward and forward angularly guided by the curved guide plate to direct the male locking hook of each succeeding turn of strip around the mandrel into the downward opening of the female hook of the preceding turn of strip, the two in- 1 1 12 tel-engaged locking hooks being thereafter bent over tion with respect to the lower portion being preset for and clinched between the pinch rolls, the angular adthe Continuous forming of the Spiral pipe Seam of the justment and spacing and position of the pinch rolls, the position of the bending roll and curved guide plate, and the angular adjustment of the mandrel upper porpipe of the desired diameter size.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1

DATED :August 12, 1975 |NVENTOR(5) I JACK P. LOMBARDI It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1, line 40, "location" should be locking Col. 4, line 13, "secuerd" should be secured Col, 9, line 64, which is the beginning of claim 4 the claim is not numbered; line 65, the first word should be --ing--(last three letters of the word receiving); line 66, first word and was omitted; line 67, first word should be plurality line 68, first word for was omitted.

Signed and Sealed this twenty-eight D ay Of October I 9 75 [SEAL] A ttest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner vfParenrs and Trademarks 

1. A non-rotating two-part mandrel for forming spiral seamed pipe from a formed strip of metal received from a forming mill having synchronously driven rollers for forming an upstanding male locking hook along one edge and an upstanding and downwardly opening female locking hook along the opposite edge, comprising: a substantially semi-cylindrical lower mandrel part secured at its inner end to a support tower projecting horizontally under the forming mill, a bending roller on the tower for bending the strip downward, the lower part having at its outer end a flat upper surface and a curved side surface on the far side of the advancing strip adapted to angularly guide the strip as it is received from the mill, an upper mandrel part having a flat lower surface plate at its outer end, a pivot pin projecting vertically upward from the flat upper surface through the surface plate and secured to one of the mandrel parts, a way formed longitudinally on the surface plate and Carrying a slide adjustable along the way, the slide carrying a guide plate curved substantially about the midline of the surface plate and adjustable up and down with respect to the plate, the surface plate being angularly adjustable about the pivot pin with respect to the mandrel lower part for forming pipes of different diameters, means for locking the plate in angularly adjusted position, a turntable in the way linked to the slide and carrying a lower pinch roll, the turntable being angularly adjustable with respect to the way and lockable in adjusted position, the lower pinch roll being adjustable up and down with respect to the surface plate, the lower mandrel post being positioned with respect to the forming mill so that the female hook of the advancing strip passes over the locking pin, the guide plate being adapted to angularly guide the strip so that the male hook of the strip on each succeeding turn of the strip about the mandrel is aligned with and enters the opening of the female hook of the preceeding turn, and an upper pinch roll rotatably carried by the tower, the pinch rolls being adjustable for continuously clinching the hooks into a spiral seam as the strip is fed around the mandrel.
 2. A non-rotating two-part mandrel for forming spiral seamed pipe from a formed strip of metal received from a forming mill having synchronously driven rollers for forming an upstanding male locking hook along one edge and an upstanding and downwardly opening female locking hook along the opposite edge, comprising: a substantially semi-cylindrical lower mandrel part secured at its inner end to a support tower and projecting horizontally under the forming mill, the lower part having a flat upper surface at its outer end, an upper mandrel part having a flat lower surface plate at its outer end, a pivot pin projecting vertically upward from the flat upper surface through the surface plate and secured to one of the mandrel parts, the surface plate having a portion projecting inwardly for moving the plate about the pivot pin to change the angular disposition of the plate with respect to the lower part, means at the inner end of the projecting portion for locking it to the lower part in a selected angular disposition, the surface plate bearing a longitudinally extending gib-way, a first slide in the way bearing a guide plate curved about the axis of the lower part pivotally secured at one side to the upper portion of the slide, motor means carried by the slide for limited adjustment of the guide plate spacing above the slide, means on the mandrel upper part for securing the slide in a selected position along the way, a second slide in the way bearing a turntable and connected by a channel-type coupling to the first slide, the turntable having limited angular adjustment relative to the way, cooperating means on the turntable and coupling for locking the turntable in a selected angular position, a lower pinch roll rotatably carried on the turntable and having an axially extending shaft substantially aligned with the way, the pinch roll shaft ends having their axes off-center from the axis of its roll-bearing center, means on the turn table slide for turning the pinch roll shaft and regulating the height of the pinch roll above the way; the lower mandrel part projecting from the tower at an angle and the forming mill rollers feeding the strip forward with its female hook passing substantially over the inner end of the mandrel and its male hook substantially over the axis of the pivot, an upper pinch roll adjustably and rotatably secured to the tower over the lower pinch roll, at least one bending roller for bending downward the strip advancing from the forming mill, and an exit conveyor for receiving pipe formed on the mandrel.
 3. A non-rotating two-part mandrel for forming spiral seamed pipe from a formed strip of metal received from a forming mill having synchronously driven rollers for forming an upstanding male locking hook along one edge and an upstanding and downwardly opening female locking hook along the opposite edge, comprising: a substantially semi-cylindrical lower mandrel part secured at its inner end to a support tower and projecting horizontally therefrom under the forming mill, the lower part having a flat upper surface at its outer end, an upper mandrel part having a flat lower surface plate at its outer end, a pivot pin projecting vertically upward through the flat upper surface and through the surface plate and being secured to one of the mandrel parts, the surface plate having a portion projecting inwardly and bearing an arcuate clamping plate adjacent the inward end of the lower part and the lower part having a cooperating clamping ear whereby the angular relation of the two parts may be selectively adjusted and then secured by bolt means through the clamping plate and ear, the surface plate bearing a longitudinally extending gib-way, a first slide in the way bearing guide plate curved about the axis of the lower part pivotally secured at its forward side to the slide and hydraulic cylinder means on the first slide for selectively adjusting the guide plate curved surface up and down about its pivoted side, means on the upper part for securing the first slide in a selected position along the way, a second slide in the way bearing a turntable and connected by a channel-type coupling to the first slide, the turntable having limited angular adjustment relative to the way and cooperating means on the turntable and coupling for locking the turntable in a selected angular position, a lower pinch roll rotatably carried on the turntable and having an axially extending shaft substantially aligned with the way and having its ends on an axis off-center from the axis of its roll-bearing center, and means on the turntable slide for turning the pinch roll shaft and thereby regulating the heighth of the pinch roll above the way; the lower mandrel part projecting from the tower at an angle and the forming mill rollers feeding the strip forward with the male hook passing substantially over the inner end of the mandrel and the female hook aligned substantially with and above the axis of the pivot pin, an upper pinch roll adjustably and rotatably secured to the tower over the lower pinch roll, at least one bending roller adjustably secured to the tower for bending downward the strip advancing from the forming mill, and an exit conveyor having spaced rollers for receiving pipe formed on the mandrel, the conveyor being adjustable up and down and angularly with respect to the mandrel; whereby a turn of advancing strip is bent downward and angularly guided by the forward side of the lower mandrel part, then continues downward to be supported by the conveyor rollers, then continues upward and forward angularly guided by the curved guide plate, the male locking hook of each succeeding turn of strip around the mandrel being guided into the downward opening of the female hook of the preceding turn of strip, the two interengaged locking hooks being thereafter bent over and clinched between the two pinch rolls, the angular adjustment and spacing of the two pinch rolls being preset, the position of the curved guide plate being positioned longitudinally of the upper mandrel part for the continuous forming of the spiral pipe seam, and the formed pipe being forced away from the mandrel by the continuous advancing of the strip from the forming mill.
 4. The mandrel defined in claim 3 adapted for receiving a laminated strip having a corrugated upper layer and a flat lower layer, the bending roller comprising a plurality of laterally spaced rollers on a common shaft for contact with the valleys of the corrugations, whereby a spiral seamed corrugated laminated pipe with uncorrugated interior is formed.
 5. The mandrel defined in claim 3 wherein the major portion of the exterior in cross section of the lower mandrel exceeds a semicircle and wherein the diameter of the semicylindrical lower mandrel part and twice the radius of the curved guide plate of the uppeR mandrel part are each less than the interior diameter of the smallest pipe to be formed on the mandrel.
 6. A non-rotating, adjustable, two-portion mandrel for forming spiral-seamed metal pipes of different diameters from a strip of standard width having an upstanding male locking hook along one edge and an upstanding, downwardly opening female locking hook along the other side; comprising: a substantially semicylindrical lower mandrel portion secured at its inner end projecting horizontally from a support tower and having a flat upper surface over the major and outer portion of its length and circularly curved under and side surfaces for substantially its full length, the curved surfaces extending at least 180* therearound, the radius of curvature thereof being smaller than the radius of curvature of the smallest diameter of pipe to be produced; an upper mandrel portion of less length than the lower portion and including a plate having a flat horizontally-extending lower surface engaging the lower portion upper surface; a vertically extending pivot pin pivotally connecting the upper and lower portions; means on the upper portion for angularly adjusting the upper portion in a horizontal direction with respect to the lower portion, and lock means for securing the upper portion in adjusted position to the lower portion; a slide carried on the upper portion plate, the plate having way means for guiding the slide longitudinally along the plate; means carried on the upper portion for adjusting the slide toward and away from the pivot pin; a turntable adapted to slide along the way means, a channel type connector connecting the turntable to the slide, the turntable being angularly adjustable with respect to the slide, and means for locking the turntable in adjusted position; a lower pinch roll rotatably carried by the turntable, means for raising and lowering the lower pinch roll a limited amount with respect to the upper portion plate; synchronously driven rolls for forming the locking hooks and for driving forward the strip rotatably carried in the tower above the mandrel for feeding the strip toward the mandrel; the mandrel lower portion projecting at an angle to the line of travel of the strip and the pivot pin being positioned to underlie the female locking hook on the outer edge of the strip; an upwardly convex curved guide plate of substantially the same radius of curvature as the mandrel lower portion being pivotally secured along one edge to the slide, motor means carried by the slide for adjustably raising the guide plate; at least one bending roller and an upper pinch roll carried by the tower and each being adjustable with respect to the mandrel; and conveyor means below the mandrel for receiving and carrying away pipe formed on the mandrel; whereby each turn of advancing strip is bent downward and angularly guided by the forward side of the mandrel lower portion, then continues downward to the region of the conveyor means, thence continues upward and forward angularly guided by the curved guide plate to direct the male locking hook of each succeeding turn of strip around the mandrel into the downward opening of the female hook of the preceding turn of strip, the two interengaged locking hooks being thereafter bent over and clinched between the pinch rolls, the angular adjustment and spacing and position of the pinch rolls, the position of the bending roll and curved guide plate, and the angular adjustment of the mandrel upper portion with respect to the lower portion being preset for the continuous forming of the spiral pipe seam of the pipe of the desired diameter size. 